| Cheminfoinvest Ltd | Financial services | 2025 |
| Cheminfosolutions Ltd | Information & communication | 2018 |
| Cherith Sound & Lighting Limited | Administrative & support | 2023 |
| Chestnut Westoning Limited | Financial services | 1998 |
| Chevronic Centre Limited | Wholesale & retail | 2001 |
| Chevronic Holdings UK Limited | Real estate | 2017 |
| Chicken George (Bedford) Limited | Hospitality | 2022 |
| Chicken George (Hitchin) Limited | Hospitality | 2020 |
| Chicken George (ST Albans) Limited | Hospitality | 2023 |
| Chicken George JNR Limited | Hospitality | 2019 |
| Chicken George Limited | Hospitality | 2011 |
| Chicken George Production Limited | Manufacturing | 2023 |
| Chicken George Property Limited | Real estate | 2024 |
| Chicken George Rugby Limited | Hospitality | 2024 |
| Chicken George Sports Limited | Hospitality | 2024 |
| Chicken George Trailer Limited | Hospitality | 2023 |
| Chicken George Truck Limited | Hospitality | 2023 |
| Chickli Ltd | Manufacturing | 2025 |
| Child of Project C.I.C. | Wholesale & retail | 2022 |
| Children to Prosper Limited | Health & social care | 2020 |
| CHILLBAR1 Limited | Professional & scientific | 2004 |
| Chilli Banana Limited | Hospitality | 2024 |
| Chiltern Consultants Limited | Professional & scientific | 2015 |
| Chiltern Court Management (Hitchin) Limited | Households | 2004 |
| Chiltern Developments (Hitchin) Limited | Construction | 2014 |
| Chiltern Forestry Limited | Extraterritorial | 2010 |
| Chiltern Properties (Hitchin) Limited | Real estate | 2020 |
| Chiltern Wood Limited | Professional & scientific | 2025 |
| Chimney Care Limited | Extraterritorial | 2017 |
| Chinese Food Centre Takeaway Limited | Hospitality | 2025 |
| Ching Court Advisory Limited | Professional & scientific | 2022 |
| Chop IT Like It’S Hot Limited | Other services | 2022 |
| Chris Goldenberg Construction Management Services Ltd | Construction | 2019 |
| Chris Hewlett PR and Artist Management Ltd | Professional & scientific | 2006 |
| Chris Jones Property Services Ltd | Other services | 2021 |
| Chris Marks Carpentry & Building Ltd | Manufacturing | 2025 |
| Chris Partington Services Limited | Financial services | 2005 |
| Chris White Software Ltd | Information & communication | 2022 |
| Chrishall Design Limited | Professional & scientific | 2004 |
| Christ Inn CIC | Administrative & support | 2009 |
| Christian TYE Consulting Ltd | Information & communication | 2024 |
| Chroma Audiology Ltd | Health & social care | 2025 |
| Chron London Ltd | Real estate | 2017 |
| Church View Hitchin Limited | Households | 2017 |
| Ciexpert Limited | Information & communication | 2011 |
| CIN and LU Ltd | Hospitality | 2026 |
| Cindies Student Nights Ltd | Other services | 2021 |
| Cinekolor Limited | Information & communication | 2011 |
| Cinetronica (UK) Ltd | Information & communication | 2023 |
| Cippers Consultants Limited | Wholesale & retail | 2025 |
| Cips Resolution Ltd | Professional & scientific | 2023 |
| Circadian Wellbeing Limited | Wholesale & retail | 2018 |
| Citrine Research Ltd | Professional & scientific | 2020 |
| City Connect Couriers Ltd | Extraterritorial | 2025 |
| Citydoc Medical Limited | Health & social care | 2011 |
| Civil Engineering Enterprises Limited | Professional & scientific | 1997 |
| CJ Sansom Limited | Administrative & support | 1989 |
| CJ Vision Ltd | Wholesale & retail | 2026 |
| Cjbros Limited | Hospitality | 2024 |
| Cjhv Developments Limited | Real estate | 2015 |
| Cjhv Investments Limited | Real estate | 2015 |
| Cjhv Mercury Holdings Limited | Financial services | 2024 |
| Cjhv Mercury Limited | Financial services | 2020 |
| CJR Financials Ltd | Professional & scientific | 2021 |
| CJR Surveying Limited | Professional & scientific | 2017 |
| CK Bespoke Refurbishments Ltd | Construction | 2007 |
| CKC Homes Limited | Real estate | 2014 |
| CKC Marketing LLP | | 2014 |
| CKC Properties Limited | Construction | 2006 |
| CKD Digital Ltd | Information & communication | 2021 |
| CKS Safety Consultants Ltd | Administrative & support | 2017 |
| CL Clarke Property Management Ltd | Real estate | 2021 |
| Claire Best Marketing Ltd | Professional & scientific | 2015 |
| Clare Fiore Business Services Limited | Administrative & support | 2006 |
| Clare Gardens Estate Management Company Limited | Real estate | 2007 |
| Clare's Inns Limited | Hospitality | 2020 |
| Clarke & Co. Property Law Ltd | Professional & scientific | 2026 |
| Claryon Ltd | Professional & scientific | 2025 |
| Classical Productions Ltd | Information & communication | 2019 |
| CLC Events Limited | Manufacturing | 2025 |
| Clean Elite Ltd | Administrative & support | 2025 |
| Clean Revolution Ltd | Professional & scientific | 2009 |
| Clean the World Ventures UK Limited | Professional & scientific | 2015 |
| Cleancore Intelligence Ltd | Information & communication | 2022 |
| Cleaning Club Collective Ltd | Administrative & support | 2026 |
| Clear Design Direction Limited | Professional & scientific | 2016 |
| Clear Edge Software Ltd | Information & communication | 2020 |
| Clearglaze Limited | Construction | 1994 |
| Clearly Nova Limited | Information & communication | 2014 |
| Clearpath Financial Holdings Limited | Financial services | 2024 |
| Clearpath Financial Ltd | Professional & scientific | 2022 |
| Clearwater Servicing Ltd | Construction | 2004 |
| Clemm Properties Limited | Real estate | 2024 |
| CLICK2PROTECT UK Limited | Financial services | 2014 |
| Climech Limited | Construction | 2019 |
| Clipper Maintenance Services Limited | Administrative & support | 1988 |
| Clma Ltd | Professional & scientific | 2026 |
| Cloud Nine Baby Limited | Wholesale & retail | 2020 |
| Clover Vets Limited | Professional & scientific | 2025 |
| Club 85 CIC | Arts & recreation | 2026 |